package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.Servlet;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.UUID;

/**
 * 文件上传和下载
 */
@RestController
@RequestMapping("/common")
@Slf4j

public class CommonController {
    @Value("${reggie.path}")
    private String Bathpath;

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) {
        //file是一个临时文件,需要转存到指定位置,否则本次请求完成后临时文件会删除
        log.info(file.toString());
        //原始文件名
        String originalFilename = file.getOriginalFilename();
        String s = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用uuid重新生成文件名,防止文件名称重复造成文件覆盖
        String filename = UUID.randomUUID().toString()+s;
        //创建一个目录对象
        File dir = new File(Bathpath);
        //判断当前目录是否存在
        if(!dir.exists()){
            //目录不存在  创建一个目录
            dir.mkdir();
        }
        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(Bathpath+filename));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(filename);
    }
    /**
     * 文件下载
     */
    @GetMapping("/download")
        public  void download(String name , HttpServletResponse response){

        try {
            //1:先通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(Bathpath+name));
            //2:输出流，通过输出流将文件写回游览器，在游览器显示图片
            ServletOutputStream outputStream =  response.getOutputStream();
            response.setContentType("image/jpeg");
            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}